While it varies based on body weight, you would have to drink quite a bit of joe to overdo it.

"It would likely take anywhere from 50-100 cups of coffee to result in a lethal dose of caffeine," Robert Glatter, an emergency physician at Lenox Hill Hospital in New York City, told USA Today. "That said, pure powdered caffeine can be lethal if a teaspoon of it is consumed at once.”

If you intake an excessive amount of caffeine, you may experience serious side effects. Glatter said many have had palpitations, dizziness, elevated blood pressure, nervousness and anxiety.

And the risk of alcohol poisoning increases even more for those who mix caffeine with alcohol, because “the person often believes and feels they are more alert,” he said. “They feel the caffeine will keep them awake and alert."

While coffee isn't likely to cause an overdose, popular energy drinks bring higher risks. In general, a 24-oz. energy drink can contain as much as 500 milligrams of caffeine. A 24-oz. Red Bull has 205 milligram of caffeine, while a Rockstar has 240 and a Monster has 244.

Researchers have also found that commercial energy drinks have been linked to heart problems.